.TH MPI_T_pvar_reset 3 "6/7/2023" " " "MPI"
.SH NAME
MPI_T_pvar_reset \-  Reset a performance variable 
.SH SYNOPSIS
.nf
.fi
.nf
int MPI_T_pvar_reset(MPI_T_pvar_session session, MPI_T_pvar_handle handle)
.fi


.SH INPUT PARAMETERS
.PD 0
.TP
.B session 
- identifier of performance experiment session (handle)
.PD 1
.PD 0
.TP
.B handle 
- handle of a performance variable (handle)
.PD 1

.SH NOTES
The MPI_T_pvar_reset() call sets the performance variable with the handle identified
by the parameter handle to its starting value. If it is not possible
to change the variable, the function returns MPI_T_ERR_PVAR_NO_WRITE.
If the constant MPI_T_PVAR_ALL_HANDLES is passed in handle, the MPI implementation
attempts to reset all variables within the session identified by the parameter session for
which handles have been allocated. In this case, the routine returns MPI_SUCCESS if all
variables are reset successfully, otherwise MPI_T_ERR_PVAR_NO_WRITE is returned. Readonly
variables are ignored when MPI_T_PVAR_ALL_HANDLES is specified.

.SH THREAD AND INTERRUPT SAFETY

This routine is thread-safe.  This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks.  However, the routine is not interrupt safe.  Typically,
this is due to the use of memory allocation routines such as 
.I malloc
or other non-MPICH runtime routines that are themselves not interrupt-safe.

.SH ERRORS

All MPI routines (except 
.I MPI_Wtime
and 
.I MPI_Wtick
) return an error value;
C routines as the value of the function and Fortran routines in the last
argument.  Before the value is returned, the current MPI error handler is
called.  By default, this error handler aborts the MPI job.  The error handler
may be changed with 
.I MPI_Comm_set_errhandler
(for communicators),
.I MPI_File_set_errhandler
(for files), and 
.I MPI_Win_set_errhandler
(for
RMA windows).  The MPI-1 routine 
.I MPI_Errhandler_set
may be used but
its use is deprecated.  The predefined error handler
.I MPI_ERRORS_RETURN
may be used to cause error values to be returned.
Note that MPI does 
.B not
guarantee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.

.PD 0
.TP
.B MPI_SUCCESS 
- No error; MPI routine completed successfully.
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_HANDLE 
- The handle is invalid.
.PD 1
.PD 0
.TP
.B MPI_T_ERR_INVALID_SESSION 
- Session argument is not valid.
.PD 1
.PD 0
.TP
.B MPI_T_ERR_NOT_INITIALIZED 
- The MPI tool information interface is not initialized.
.PD 1
.PD 0
.TP
.B MPI_T_ERR_PVAR_NO_WRITE 
- The performance variable can not be written or reset.
.PD 1
.PD 0
.TP
.B MPI_ERR_OTHER 
- Other error; use 
.I MPI_Error_string
to get more information
about this error code. 
.PD 1

